Anvil device



July 22, 1969 J. w. CROTHERS ET AL 3,456,483

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Filed June 28, 1966 United States Patent 3,456,483 ANVIL DEVICE James W.Crothers and Frederick R. Satterlee, Hopkinsville, Ky., assignors toThomas Industries Inc., Fort Atkinson, Wis., a corporation of DelawareFiled June 28, 1966, Ser. No. 561,160 Int. Cl. 1821i 13/02; 821d 41/02,37/02 US. Cl. 72-478 9 Claims ABSTRACT OF THE DISCLOSURE This inventionrelates generally to an anvil device and more particularly to an eyeletsetting or clinching anvil.

It has heretofore been the practice in designing and constructing anvilsand, in particular, anvils for use in setting or flaring eyelets, tomake the anvils of a onepiece construction. Conventionally, suchone-piece anvils are made of tool steel, machined to close tolerancesand heat treated in an attempt to impart the desired physical propertiesto the anvil. The various portions of the anvil which assist in theflaring of eyelets require diflferent hardness or toughness in order toresist wear or breakage of the particular portions. With one-piece anvilconstructions, it is necessary to settle for a compromise heat treatmentthat is not necessarily the best for all wear points on the anvil. Thisuniform compromise heat treatment leads to excessive breakage andpremature wear with consequently high costs of production throughreplacement expenditures.

It is the primary object of the subject invention to overcome the abovedisadvantages inherent in prior anvil devices by providing an anvilwhich allows the various portions of the anvil to be given the properhardness and toughness to thereby eliminate excessive breakage andpremature wear.

A feature of the present invention is to provide an anvil comprisingseparable portions wherein each portion may be given its propercharacteristics of hardness and toughness to resist wear and breakage.

Another feature of the present invention is to provide an anvil whichallows for ease of assembly and disassembly to thereby allow individualseparable portions of the anvil to be individually replaced uponbreakage or excessive wear.

A further feature of the present invention is to provide an anvil havinga support shank which supports other portions of the anvil and whichshank includes means to allow ready disassembly of the anvil forreplacement of individual components thereof.

Another feature of the present invention is to provide an anvil devicethat may be cooperatively associated with eyelet supply means and aset-cup assembly to define eflicient eyelet setting apparatus.

Another feature of the present invention is to provide an anvil which iseconomical to manufacture and highly efiicient in operation.

Further objects and advantages of our invention together with theorganization and manner of operation thereof, may best be understood byreference to the following description taken in connection with theaccompanying drawing, in the several figures of which like referencenumerals identify like elements, and in which:

FIGURE 1 is a vertical view, partly in section, showing ice the anvil ofthe present invention supported in an operative position and cooperatingwith a set-cup assembly to introduce eyelets onto the anvil;

FIGURE 2 is a fragmentary vertical view, partly in section, showing theanvil in cooperation with the set-cup assembly after an eyelet has beenclinched upon two members to be joined; and

FIGURE 3 is a vertical view, partly in section, illustratin-g the anvilof the subject invention in disassembled relation.

Referring now to the drawing, a support mounting 10, which may form apart of any machine or apparatus with which the present invention isused, has a cylindrical recess 12 adapted to receive a lower cylindricalportion 14 of an anvil, shown generally at 16. The anvil 16 ispositioned to cooperate with a set-cup assembly, shown generally at 18,and an eyelet guide 20 to effect clinching of eyelets or rivets 22. Theeyelets are fed by gravity from a hopper 24 through the guide 20 to aposition where they are introduced onto the anvil 16 as will bedescribed hereinbelow.

Referring to FIGURE 1, the set-cup assembly 18 is of conventionalconstruction and includes a tubular set-cup 26 which is fixedly securedto a support member 28 for vertical up and down movement. The set-cup 26slidably receives a pick-up pin 30 within a central recess 32 therein.The pick-up pin 30 is biased downwardly within the recess 32 by a coilspring 34 which acts against an upper portion 36 of the pick-up pin. Theset-cup 26 has a generally concave annular end surface 38 which servesto engage a flared portion 40 on the eyelets 22 when the set-cupassembly is moved downwardly.

The anvil 16 comprises an upper pilot portion 42, a flaring insert 44,and a shank portion 46. The shank 46 has a lower cylindrical portion 14which is received within the support member 10 as hereinabove described.An upper cylindrical portion 48 of the shank 46 is preferably madecoaxial with the lower portion 14 and may have any length suitable to aproduction installation, while providing sufficient column strength toresist axial loading of the shank. A coaxially disposed cylindrical bore50 is provided in the upper end 48 of shank 46 to receive a cylindricalportion 52 of the pilot 42 and has a depth greater than that necessaryto fully receive the cylindrical portion 52 when in assembled position.The upper portion 48 of shank 46 includes a longitudinal slot 54 whichextends radially through the upper portion 48 to intersect theperipheral surface thereof and the axial bore 50. The slot 54 createstwo upstanding leg or wall portions 51 and '53 in the upper portion 48of shank 46 which are bent inwardly toward each other causing thecentral bore 50 therein to be narrower at the upper portion adjacent theend surface 55 than at its lower extremity. The leg portions 51 and 53form a biased frictional gripping engagement with the cylindricalportion 52 of the pilot 42 when in assembled position to thereby retainthe pilot 42 within the shank 46. Noting FIGURE 1, the slot 54intersects end surface 55 and has a longitudinal length equal to that ofbore 50'. A space will thus be provided between the lower end of theportion 52 and the bottom of slot 54 when in assembled position to allowa separating tool to be inserted therein for disassembling the anvil. Itwill be understood that more than one slot may be provided in shank 46if the shank is made of a diameter sufficient to maintain the necessarysupport strength.

The pilot portion 42 of anvil 16 includes a frustoconical peripheralsurface 56 which tapers outwardly when considered in a directiondownward along the axial length from the upper end thereof. Theperipheral surface 56 is formed coaxial with the longitudinal centerlineof the lower cylindrical portion 52. The cylindrical portion 52 has asmaller diameter than the diameter of the frusto-conical surface 56adjacent the cylindrical portion 52 so as to form a radial shoulder 58therebetween (FIG- URE 3). A beveled edge 61 is preferably provided onthe lower end of pilot 42 to assist in guiding the cylindrical portion52 into bore 56 of shank 46. A generally V-shaped or conical recess 57is provided in the upper end 55 of pilot 42 to recieve the lower end ofpick-up pin 30 and assist in proper alignment of the guiding pin and theanvil 16 during a flaring or clinching operation.

The flaring insert 44 comprises a generally annular member having acentral bore 60 extending therethrough which has a diameter such that itwill slidably and snugly receive the lower cylindrical portion 52 ofpilot 42 therethrough when in assembled relation. An upper end surface62 of insert 44 abuts the radial shoulder 58 of pilot 42 when the insertis assembled on the cylindrical portion 52 and has an annular area equalto that of the shoulder 58. An annular surface portion 64 on insert 44defines a generally arcuate surface adjacent end surface 62 and forms acontiguous outwardly directed arcuate curved surface with thefrusto-conical surface 56 of pilot 42 when in assembled position onportion 52. The annular arcuate surface 64 cooperates with surface 56 toflare the tubular end of an eyelet 22 when the eyelet is brought intoabutting engaging relationship therewith as it is forced downward uponthe pilot portion 42.

The above described separable portions comprising the anvil 16 are madeof material suitable to withstand the forces created in flaring andclinching eyelets and have a toughness and hardness adequate to resistbreakage and premature wear. For example, the pilot portion 42 and theflaring insert 44 are preferably made of a high carbon, high chrome,high nickel steel with the pilot portion 42 being heat treated to ashock resistant hardness of Rockwell C 5456, while the flaring insert 44is heat treated to a wear resistant hardness of Rockwell C 6l63. Theshank 46 is preferably made of drill rod steel hardened to Rockwell C45-50 to thereby result in high toughness and impact loading resistanceproperties.

The separable members of the anvil 16 are assembled by mounting theflaring insert 44 onto the cylindrical portion 52 of pilot 42 andthereafter inserting the cylindrical portion 52 into the central bore 50of shank 46. The upstanding leg portion 51 and 53 of upper portion 48 ofshank 46, having been previously bent inwardly, frictionally engage andgrip the cylindrical portion 52 of pilot 42 to thereby hold pilotportion 42, flaring insert 44, and shank 46 in fixed assembled relation.The assembled anvil 16 may then be inserted into the supporting memberin a position to underlie the guide channel which serves to guide holloweyelets 22 into position for downward movement onto the pilot portion 42of the anvil. Two work pieces, such as plates 68 and 70 (FIGURES l and2) may be positioned adjacent to and overlying the arcuate surface 64 offlaring insert 44 in any conventional manner, which plates 68 and 72 areto be secured together by a clinched eyelet. When the plates are inposition over the anvil 16, the set-cup assembly 18 is moved downwardlywhereupon pick-up pin 30 is passed through the center of a hollow eyelet22 and thereafter contacts the conical recess 57 in pilot portion 42 toguide the eyelet 22 downward onto the frustoconical surface 56.Continual downward movement of the set-cup 26 causes the annular concavesurface 38 thereof to engage the flange 40 on the eyelet to therebyforce the eyelet downwardly upon the pilot portion 42 whereupon thelower end of the eyelet will be flared or set outwardly upon engagingthe radially extending surface 64 of flaring insert 44. The flared endof the eyelet will curl back upon itself such that a continuous curledsurface 72 is formed which cooperates with the upper flange portion 40to thereby clinch the two plates 68 and 70 together.

With the above described anvil being comprised of separable portions, itcan be readily appreciated that any one of the individual separableportions could be replaced very easily upon unexpected failure orexcessive wear with the resultant decrease in expense attendant priorart unitary constructions.

While a particular embodiment of our invention has been shown anddescribed, it will be obvious to those skilled in the art that changesand modifications may be made without departing from the invention inits broader aspects, and, therefore, the appended claims cover all suchchanges and modifications as fall within the true spirit and scope of myinvention.

We claim:

1. An anvil device for setting a tubular eyelet comprising a pilotportion adapted to slidably receive the eyelet in coaxial relationthereon, a flaring means associated with said pilot portion in fixedrelation therewith and adapted to flare an end of the eyelet radiallyoutwardly when the eyelet is moved longitudinally of said pilot portionto engage said flaring means, said flaring means having a higherRockwell hardness than said pilot portion to provide high wearresistance, and a separable shank portion adapted to releasably supportsaid pilot portion and said flaring means, said shank portion having alower Rockwell hardness than said flaring means to provide high impactloading resistance.

2. The device as defined in claim 1 wherein said flaring means comprisesa separable annular member disposed in coaxial relation with said pilotportion and having a generally radially extending arcuate surfacethereon to engage said end of the eyelet for flaring it radiallyoutwardly upon engagement therewith.

3. The device as defined in claim 1 wherein said pilot portion includesa generally frusto-conical peripheral surface to receive said end of theeyelet in coaxial sliding relation thereon and a radial shoulder axiallydisposed from the outer end of said pilot portion to engage said flaringmeans, said peripheral surface diverging outwardly along the length ofsaid pilot portion from said outer end to initiate flaring of said endof the eyelet prior to engagement of the eyelet with said flaring means.

4. An anvil device for setting a tubular eyelet comprising a pilotportion adapted to slidably receive the eyelet in coaxial relationthereon, a flaring means coaxially disposed on said pilot portion at aposition axially removed from the outer receiving end thereof andincluding an annular radial arcuate portion forming a contiguous surfacewith said pilot portion to effect radial outward flaring of an end ofthe eyelet when the eyelet is moved longitudinally of said pilot portionto engage said flaring means, and a shank portion adapted to supportsaid pilot portion and said flaring means.

5. An anvil device for setting a tubular eyelet comprising a pilotportion adapted to slidably receive the eyelet in coaxial relationthereon, a flaring means associated with said pilot portion to flare anend of the eyelet radially outwardly when the eyelet is movedlongitudinally of said pilot portion to engage said flaring means, and ashank portion adapted to support said pilot portion and said flaringmeans, said shank portion comprising a member separable from said pilotportion and said flaring means, said shank portion having alongitudinally extending bore therein to receive said pilot portion insupporting relation.

6. The device as defined in claim 5 wherein said shank portion includesa longitudinally extending radial slot intersectiong said bore and theouter peripheral surface of said shank to allow wall portions of saidshank portion to be bent inwardly whereby said bore will be tapered andthereby frictionally grip said pilot portion in assembled position.

7. The device as defined in claim 6 wherein said longitudinallyextending bore and slot are of greater length than the length of saidpilot portion received within said bore to allow a separating tool to beinserted between the bottom of said longitudinally extending slot andthe bottom end of said pilot portion whereby said pilot portion may beseparated from said shank portion.

8. The device defined in claim 7 wherein said pilot portion includes agenerally frusto-conical surface to slidably receive the eyelet thereon,and wherein said flaring means comprises a separable annular membercoaxially disposed on said pilot portion and includes an annularradially extending arcuate surface associated with said frusto-conicalsurface of said pilot portion to effect flaring of the eyelet, saidpilot portion and said flaring means being supported by said shankportion.

9. In combination: an anvil device for setting a tubular eyeletcomprising a pilot portion adapted to slidably receive the eyelet incoaxial relation thereon, a flaring means associated with said pilotportion to flare an end of the eyelet radially outwardly when the eyeletis moved longitudinally of said pilot portion to engage said flaringmeans, and a shank portion adapted to support said pilot portion andsaid flaring means, said shank portion comprising a separable portionincluding means to releasably support said pilot portion and saidflaring means, said shank portion further including a slot therein forreceiving a separating tool to facilitate disassembly of said shankportion from said pilot portion and said flaring -means; means tosupport a supply of eyelets to be set or flared, said means includingguide means to position the eyelets preparatory to setting; and aset-cup assembly adapted to engage an eyelet when in said preparatoryposition and to cooperate with said anvil device to etfect a setting ofthe eyelet.

References Cited RICHARD J. HERBST, Primary Examiner E. SUTTON,Assistant Examiner US. Cl. X.R.

